Neither of the boys was wearing a seatbelt.
Tauranga Fire Brigade senior station officer Phil Price and two paramedics were flown to the island while Omokoroa volunteer firefighters and Katikati St John staff were transported via the Matakana Island barge.
The boys were conscious and still inside the vehicle when rescue workers arrived.
"They were not heavily trapped but the nature of their injuries meant they certainly weren't walking away from it," Mr Price said.
"They boys were stabilised, one had a special splint put on his leg and we basically prepared them for transport."
When the ambulance arrived at the scene, the boys were put on backboards and lifted out through the boot of the car.
"They had to cut the back of the seats out so they could slide them through the back of the vehicle," Mr Brettkelly said.
A cousin said the family had a gathering because their sister was visiting from Auckland.
"They had a bit to drink last night and one of the uncles wanted to go home. They crashed on the way back," he said.
Glen Proctor, owner of the Matakana Island ferry, said it was fortunate it was high tide, as passage to the island at low tide "was almost impossible" due to shallow waters.
Police said a blood sample was taken from Aidyn at the scene. With APN
